Improving odor of isopropanol

Abstract

Methods for deodorizing lower alcohols such as ethanol and isopropyl alcohol and their oxy derivatives such as ethers and esters are disclosed, including contacting these compounds with a deodorizing contact mass comprising, on a support, metals and/or metal oxides, preferably of the metals of Group IB, VIB and VIII of the Periodic Table, where the metal oxides are at least partially reduced to metal and the deodorizing contact mass has a minimum particle dimension of greater than about 0.254 mm so as to be in a form suitable for use in a fixed bed contacting process. In a preferred embodiment, isopropyl alcohol is deodorized employing such deodorizing contact masses, preferably comprising Group VIII metals such as nickel, iron, cobalt and the like, on a support, so that the contact mass has a surface area less than about 1,500 m2 per gram. Overall isopropyl alcohol finishing procedures are also disclosed employing such deodorizing methods in combination with extractive distillation procedures to produce a high grade, e.g., 91%, and/or anhydrous grade isopropyl alcohol from a crude isopropyl alcohol stream containing more than about 0.0005 percent water.

What is claimed is: 
     
       1. A method for deodorizing isopropyl alcohol wherein isopropyl alcohol is contacted with a deodorizing contact mass consisting essentially of metals or metal oxides incorporated in a porous support wherein said metal oxides are at least partially reduced to metal, said metals and oxides of the metals being selected from the group consisting of Groups IB, VIB and VIII of the Periodic Table and mixtures thereof and said support being selected from the group consisting of Kieselguhr, silica, alumina, silica/alumina, carbon, clay zeolites, refractory oxides, and mixtures thereof, and wherein said deodorizing contact mass has a minimum particle dimension of greater than about 0.01 inch so as to be in a form suitable for use in a fixed bed contacting process. 
     
     
       2. The method of claim 1 wherein said deodorizing contact mass has an effective surface area of less than about 1,500 m 2  /gram. 
     
     
       3. The method of claim 1 wherein said porous support has an effective surface area of between about 1 and 1,000 m 2  /gram. 
     
     
       4. The method of claim 1 wherein said metal is selected from the group consisting of nickel, cobalt, iron, palladium, rhodium, ruthenium, platinum, iridium, osmium, tungsten, copper and mixtures thereof. 
     
     
       5. The method of claim 1 wherein the isopropyl alcohol is a stream of isopropyl alcohol and water. 
     
     
       6. The method of claim 5 wherein metals used are selected from Group VIII of the Periodic Table. 
     
     
       7. The method of claim 5 wherein said stream of isopropyl alcohol includes from about 0.0005 to 90 weight percent water. 
     
     
       8. The method of claim 5 wherein said deodorizing contact mass has an effective surface area of less than about 1,000 m 2  /gram. 
     
     
       9. The method of claim 5 including distilling said stream of isopropyl alcohol in a first tower at a temperature of between about 80° and 130° C., and a pressure of between about 5 and 15 psig, so as to produce a liquid stream of isopropyl alcohol from the bottom of said first tower, containing between about 40 and 90 weight percent water, and to produce an overhead vapor stream from said first tower containing undesirable impurities. 
     
     
       10. The method of claim 9 including distilling said liquid stream of isopropyl alcohol containing between about 40 and 90 weight percent water in a second tower at a temperature of between about 80° and 120° C., and a pressure of from about 5 to 15 psig, so as to produce a highly concentrated liquid stream of isopropyl alcohol from the top of said second tower, said stream containing between about 9 and 15 percent water, a bottom stream from said tower comprising water, and a side stream from said tower comprising heavy impurities. 
     
     
       11. The method of claim 10 including condensing an overhead vapor stream comprising isopropyl alcohol from said second tower, to produce said stream containing between about 9 and 15 percent water, and distilling said isopropyl alcohol stream in a third tower maintained at a temperature of between about 75° and 110° C., and a pressure between about 5 and 15 psig, so as to remove a highly purified isopropyl alcohol stream in a liquid state from the bottom of said third tower, said stream containing between about 9 and 15 percent water, and an overhead vapor stream from said third tower comprising light impurities. 
     
     
       12. The method of claim 11 wherein said contacting with said deodorizing contact mass is carried out utilizing said overhead stream of isopropyl alcohol withdrawn from said second tower. 
     
     
       13. The method of claim 11 wherein said contacting with said deodorizing contact mass is carried out with said liquid stream of isopropyl alcohol withdrawn from the bottom of said third tower. 
     
     
       14. The method of claim 7 wherein said stream of isopropyl alcohol comprises the product stream from an alcohol dehydration process. 
     
     
       15. The method of claim 5 wherein metals used are selected from the group consisting of nickel, cobalt, iron, palladium, rhodium, ruthenium, platinum, copper, tungsten, and mixtures thereof.